Information storage articles employing resilient locking sleeves

ABSTRACT

A tape spool and cover are latched together by a tubular sleeve arrangement. A hollow core tape spool has an inner frustroconical camming surface adjacent an axially outwardly facing shoulder. A releasable latch includes a unitary resilient sleeve inserted into the hollow core and is cammed radially inwardly for creating radial outward forces on the opposite sleeve end outside the spool. A first axial end portion of the sleeve has a first type locking resilient finger extending out of the hollow core and a second type resilient finger in locking engagement with the hollow core tape spool. A radially inwardly extending annular rib divides the first and second axial end portions to provide a bending moment transfer ring. The slots defining the axially extending fingers extend to and preferably into the rib for providing a moment bridge for transferring the radial inward compression on the second axial end portion to a radially outwardly exerting force in the first axial end portion. It is preferred that such slots terminate on or near a common circumferential line extending around the sleeve. The outer end portion of the first type of fingers includes a latching shoulder, plus a camming surface for enabling radial inward camming all first type fingers for enabling releasable engagement between the tape spool and a cylindrical cover.

United States Patent [1 1 Fraser, J r. et al.

[ Sept. 24, 1974 INFORMATION STORAGE ARTICLES EMPLOYING RESILIENTLOCKING SLEEVES [75] Inventors: Harvey R. Fraser, Jr.; Richard T.

Larson, both of Boulder; Helfried O. Rinkleib, Longmont, all of C010.

[73] Assignee: International Business Machines Corporation, Armonk, N.Y.

[22] Filed: Aug. 6, 1973 [21] Appl. No.: 386,234

[52] US. Cl 285/319, 242/685, 279/49 [51] Int. Cl. F161 39/00 [58] Fieldof Search 285/319, 315, 322, 39;

Primary ExaminerJordan Franklin Assistant Examiner-Peter NerbunAttorney, Agent, or Firm-Herbert F. Somermeyer [5 7] ABSTRACT A tapespool and cover are latched together by a tubu lar sleeve arrangement. Ahollow core tape spool has an inner frustro-conical camming surfaceadjacent an axially outwardly facing shoulder. A releasable latchincludes a unitary resilient sleeve inserted into the hollow core and iscammed radially inwardly for creating radial outward forces on theopposite sleeve end outside the spool. A first axial end portion of thesleeve has a first type locking resilient finger extending out of thehollow core and a second type resilient finger in locking engagementwith the hollow core tape spool. A radially inwardly extending annularrib divides the first and second axial end portions to provide a bendingmoment transfer ring. The slots defining the axially extending fingersextend to and preferably into the rib for providing a moment bridge fortransferring the radial inward compression on the second axial endportion to a radially outwardly exerting force in the first axial endportion. It is preferred that such slots terminate on or near a commoncircumferential line extending around the sleeve. The outer end portionof the first type of fingers includes a latching shoulder, plus acamming surface for enabling radial inward camming all first typefingers for enabling releasable engagement between the tape spool and acylindrical COVCI'.

19 Claims, 7 Drawing Figures Ila PAIEMEMEPMM 3,83%690 INFORMATIONSTORAGE ARTICLES EMPLOYING RESILIENT LOCKING SLEEVES BACKGROUND OF THEINVENTION The present invention relates to insertable lockingmechanisms, particularly of the tubular type, for use with hollow corearticles.

Spools for supporting magnetic media spirally wound thereon haveemployed various mechanisms for attaching the spool to rotatablesupports and/or dust covers. Since such spools should be low cost, anysuch locking mechanisms should have a corresponding low cost. Further,if the mechanism is manufactured separately of the spool, the assemblyof the two parts should be extremely simple and low cost.

Some tape-containing spools are usable with automatic apparatus. Suchautomatic apparatus automatically engages and disengages the lockingmechanisms on the spool. Because of desired low cost, it is highlydesirable that such locking mechanisms be manufactured using plasticmolding processes employing known resilient plastic materials. Also,because of the contamination problem of magnetic tape causing dropoutsand the like, the locking mechanisms should be carefully designed toavoid wear. That is, when the locking mechanism engages automaticapparatus for spool support opening or closure, reducing wear minimizesthe amount of debris generated during each attachment or closure. This,in turn, reduces the exposure for magnetic recording errors caused bysuch debris being generated in the immediate vicinity of a recordingmedium.

Further, many automatic apparatus require for avoiding tape positionerrors during spool rotation the spool to be precisely centered;accordingly, any locking mechanism should be self-centering not only onthe spool, but also in the locking engagement portion. This centering isimportant for reducing vibrations when the spool is being rotated athigh rotational velocities. The force required to engage and disengagethe locking mechanism should be carefuily controllable. Such forcesshould be chosen to be sufficient to minimize the amount of powerrequired, but should be sufficiently strong to ensure that the spool oftape is always affixed to either the closure or the attached apparatusin a secure manner. These camming forces are affected by wear andtolerances of manufacture.

An example of an information media storing article with which thepresent invention may be successfully employed is shown in the commonlyassigned copending patent application, Ser. No. 318,954, filed Dec. 27,1972.

SUMMARY OF THE INVENTION A sleeve-type insert constructed in accordancewith the present invention and being particularly adaptable forinsertion into a hollow core member, such as the hollow core of a tapespool, consists of a unitary cylindrical body having first and secondaxial end portions and consisting of resilient material. The sleevepreferably, but not necessarily, includes an annular radially inwardlyextending rib separating the first and second axial end portions. Eachaxial end portion has a plurality of slots extending axiallyapproximately from the area of the rib to the respective axial ends suchthat each axial end portion consists of a plurality of axially extendingintegrally formed resilient fingers. The slots in the first and secondaxial end portions are circumferentially displaced such that a stresstransferring bridges in the area of the rib extends between fingers inthe opposite axial end portions.

In a preferred form of the invention, afirst axial end portion includesa plurality of locking fingers each having a radially extending shoulderat the outward end portion, which also is the axial end of the firstaxial end portion. Additionally, a second type of axially extendingfingers, shorter than the first type, is disposed intermediate two ofsaid first type of fingers. The second type of finger has a radiallyextending latch detent for insertion into a receptacle portion of thehollow core member into which the sleeve is inserted. It is preferredthat the outer end portions of the first type of fingers in the firstaxial end portion have all the same dimensions. Hence, each two firsttype fingers bracketing a second type finger extend circumferentiallyaround the outer axial end of the second type of fingers.

The second axial end portion has a plurality of slots ending at the ribportion immediately adjacent the first type of fingers. It is preferredthat such second axial end portion slots be centrally located betweenadjacent slots bordering each of the first type of fingers. In one formof the invention, the slots defining each second type of finger endadjacent a broad circumferential finger of the second axial end portion.In another version of the invention, there is an additional slotextending toward the rib end portion of the second type of first axialend portion fingers.

In the most preferred form of the invention, the slots in the first andsecond axial end portions both terminate approximately along a commonplane transverse to the axis of the sleeve. Hence, the termination ofeach slot is on a circumferential line somewhere in the area of the rib.Overlapping or underlapping the slots varies stress concentrations,preloading displacements, and load or stress transfers.

The invention also contemplates the combination of the above-describedsleeve inserted into a special receptacle formed in the hollow coremember, preferably the core member of a magnetic tape spool. Such coremember has an open axial end having a first cylindrical end portion. Atthe inner end of the cylindrical end portion is an annular shoulderfacing such open axial end. At the radial inner end of the axial facingshoulder is a frustro-conical cam. The inside diameter of thefrustro-conical cam begins with a diameter greater than the outsidediameter of the second axial end portion and recedes in a direction awayfrom the open axial end to a diameter substantially smaller than theoutside diameter of the sleeve. The sleeve, inserted with the secondaxial end portion, is radially compressed by the frustro-conical cam.Additionally, the hollow core member has a plurality of detents forreceiving the detent members on the axial end portions of the secondtype of fingers. The sleeve is inserted until those detents are latchedin such receptacles. The sleeve is firmly held in the hollow core memberby the resilient urging of the second type of fingers by the radialcompression of the second axial end portion. The first type of fingersextends axially outwardly beyond the first axial end portion of thehollow core member for receiving a cover and latching same to the spool.Such first type fingers are radially inwardly urgeable against the forcetransmitted thereto by the fingers of the second axial end portion.

The arcuate surfaces of the axial end portion of the first type offingers have a radius of curvature in accordance with a minimum ofradius of the first axial end portion when being cammed radiallyinwardly for latching or unlatching action. This arrangement reduceswear. It is preferred that the radial extension on both the first andsecond types of fingers in the first axial end portion be outward.

When inserted into the hollow core member, the sleeve insert rib portionis suspended in a free space between the axially facing shoulder and theengagement of the second type of fingers with the detent receptacles.This arrangement facilitates transfer of forces in a symmetrical mannerto all of the first type of fingers which facilitates the use of acylindrical tool for simultaneously and equally radially inwardly urgingall of the first type fingers away from engagement with the innerdiameter of the hollow core member thereby releasing a cover or sleevelatched to the hollow core member. A spool support member may also beengaged to the spool through the use of the radial shoulders on theaxial end portions of the first type of fingers.

The foregoing and other objects, features, and advantages of theinvention will be apparent from the following more particulardescription of the preferred embodiments of the invention, asillustrated in the accompanying drawing.

The Drawing FIG. 1 is a diagrammatic sectional view of a stressed sleevein one axial end portion of a hollow core member.

FIG. 2 is a perspective view of the stressable sleeve of the presentinvention.

FIG. 3 is an exploded simplified perspective view, partially in section,of a spool storage cartridge employing the present invention.

FIG. 4 is an enlarged and simplified fragmentary central cross-sectionaldiagrammatic view of a cartridge illustrating one aspect of the lockingmechanism for the FIG. 2 illustrated cartridge in a closed and lockedrelationship. The sleeve is not separately shown.

FIG. 5 is a simplified enlarged fragmentary crosssectional diagrammaticview, similar to FIG. 4, showing a cartridge supported via a stressedsleeve.

FIG. 6 is a simplified enlarged fragmentary crosssectional diagrammaticview similar to FIG. 4 of a cartridge being opened.

FIG. 7 is a simplified partial diagrammatic showing of an improved endconfiguration for locking fingers on a sleeve insert.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now more particularlyto the drawing, like numerals indicate like parts and structuralfeatures in the various views and diagrams. Sleeve 10 is insertable intohollow core member 44 via open axial end 48. Hollow core member 44includes a hollow cylindrical axial end portion 11 with an insidediameter substantially greater than the outside diameter of cylindricalsleeve 10. At the axial inner end of axial end portion 11 is annularoutward axial facing truncated conical annular shoulder 12. Axiallyinward of annular shoulder 12 is frustro-conical tapered ramp or cam 13.Ramp 13 centers insert 10 inside hollow core member 44 andsimultaneously exerts radial inward forces on all fingers 14 of thesecond axial end portion of sleeve 10. This radial inward moment istransferred via central stress transferring section 15 to a set ofaxially outwardly extending locking fingers 52. The transmitted forcesresult in fingers 52 being radially outwardly urged against the innerdiameter of hollow core member 44 at its one axial end 48. Additionally,the same forces generated on fingers 14 are transmitted through centralsection or rib 15 to a plurality of sleeve retaining axially extendingfingers (second type) 17. Each finger 17 has a radially outwardlyextending detent l9 engageable into detent receptacle or aperture 20 inaxial end portion 11 of hollow core member 44. Detents 19 firmly retainsleeve 10 inside hollow core member 44.

Each of the locking fingers 52 extends axially outwardly beyond open end48. Each finger has a radially outwardly extending locking shoulder 64spaced from axial end 48 for receiving a tubular cover 26, laterdescribed, for locking same to the spool, which includes core member 44.Cover 26 includes a camming surface which engages camming surface 62 ofaxial outer end portion 152 urging all of the locking fingers 52simultaneously and symmetrically radially inward, such that the cammingsurface on the cover slides over surface 62 and then engages lockingshoulder 64. Fingers 52 return to the radial outward position forlatching the cover securely to the spool member.

To reduce wear, it is desirable that the tubular cover 26 move over thespool in a truly concentric manner. To this end, all of the outwardportions 152 of locking fingers 52 are identically formed; i.e., theyhave the same circumferential extent. To achieve this result, the twolocking fingers 52a and 52b bracketing a second type finger 17 have acircumferentially reduced portion adjacent the second type fingers 17.Beyond the outer axial extent of each finger 17, as at detent 19,fingers 52a and 52b have a circumferentially enlarged portion to achievethe above-stated results. In a preferred form of the invention, all offingers 52 are constructed as shown for fingers 52a and 52b bracketing asecond type finger 17. In one constructed version of the invention, foursets of fingers 52a, 52b and second type fingers 17 constituted thefirst axial end portion of a sleeve.

Second axial end portion, including fingers 14, in one constructedembodiment, had fingers of different circumferential extents. Firstfingers 14a circumferentially bracket elongated slots 23 and 24 betweentwo adjacent first type .or locking fingers 52. The second axial endportion also has circumferentially enlarged fingers 14b with acircumferential extent bracketing second type finger 17 of the firstaxial end portion and the two adjacent slots 25. The radial inwardcompression of fingers 14b not only radially outwardly urge fingers 17,respectively, but also assist in the radial out ward urging of fingers52a and 52b, respectively. Because of differing circumferential extentsbetween fingers 14a and 14b, it is important that the different sizefingers be symmetrically disposed about the sleeve. Additionally, a slotmay be provided within finger 14b as indicated by dotted line 27, whichslot may have an axial extent less than the other slots within thesecond axial end portion. Other configurations can readily beenvisioned, including some alternatives discussed later.

The annular rib 15 can have an axial extent as shown by dotted lines 29in FIG. 2. The slots in both the first and second axial end portionsextend into the rib portion up to a common circumferential line 30axially centrally of rib 15. This arrangement provides for good bendingmoment transfer between the two axial end portions. By making a slotshorter, the bending moment is reduced; that is, if the slot did notterminate in approximate vicinity of rib 15, the radial inward urging offingers 14 in the second axial end portion would not be fullytransmitted to the fingers in the first axial end portion. That is, theradial outward urging of locking fingers 52 would be reduced byshortening the slots. Accordingly, for maximum controlled forcetransfer, the slots in the first and second axial end portions shouldterminate in the proximate vicinity of common circumferential line 30,which defines a common plane transverse to the axis of sleeve 10. It ispermissible within the invention to underlap the slots to the outeraxial perimeter of rib 15 such as identified by lines 29 in FIG. 2.

It should also be noted that the circumferential extent of fingers 14,52, and 17 is much greater than the circumferential extent of the slots.This is a design choice to provide maximum forces being transferred fromthe radial inward urging of fingers 14 to the fingers 17 and 52 in thefirst axial end portion.

In a constructed embodiment of the invention, the axial length offingers 14 is approximately one-half of the axial length of fingers 52.This means that the radial inward force exerted on fingers 14 byfrustro-conical camming surface 13 is approximately twice as great asthe radial outward urging of fingers 52 at the actual outward endportions 152. Also, fingers 17 in the first axial end portion aresomewhat shorter than looking fingers 52. The result is that the radialoutward urging, i.e., the locking force, on detents 19 is substantiallygreater than the locking force exerted on locking fingers 52. In suchconstructed embodiment, locking fingers 17 have a somewhat greater axiallength than second axial end portion fingers 14, the actuating fingersin the radial force locking engagement provided in the first axial endportion. This arrangement is a best mode of practicing the invention.Keeping the force on detents 19 greater than on locking fingers 52ensures that sleeve stays secured to the hollow core even when fingers52 are moved radially inwardly, as later described.

The internal surface features of hollow core member 44 cooperate withthe geometric configuration of sleeve 10 to provide optimum controlledtransfer of the radial inward forces on fingers 14 to radial outwardforces on locking fingers 52. The axial end cylindrical portion 1 1 hasan inside diameter greater than the outside diameter of sleeve 10. Thispermits sleeve 10 to be suspended in free space inside this portion.Axially outwardly facing shoulder 12 reduces the inside diameter ofhollow core member 44 to a diameter less than the outside diameter ofsleeve 10. Then, frustro-conical surface 13 further reduces the insidediameter for ex erting radial inward forces on fingers as sleeve 10 isinserted into member 44. The axial lengths of fingers l4 and 52 areselected such that annular rib 15 is disposed in the free space withinaxial cylindrical end portion 11 just axially outward of shoulder 12.Rib 15 and the finger portion in juxtaposition thereto are in free spacepermitting free movement of the sleeve in this area for efficientlytransferring radial forces from fingers 14 to fingers 52. The annularspace between sleeve 10 and portion 11 in the vicinity of rib l5 permitsuninhibited movements for enabling the abovementioned efficient transferof forces. Rib 15 is an annular fulcrum for the transfer of the radialforces. Without rib l5, stress concentrations in the area where thefingers join about common line 30 could cause fractures with resultantdecreased efficiency of energy transfer between the radially urgedfingers.

The combination of hollow core member 44 and sleeve 10 is best used inconnection with a tapecontaining cartridge 16 shown in FIG. 3. A tubularcover 26 is releasably locked to core member 44 via locking fingers 52locking shoulders 64. In this regard, in cartridge 16, tubular cover 26axially slides over core 44 to engage radially enlarged base or spoolflange 46 of single-flanged spool 28. Cover 26 has open end 32 and atapered and partially closed end 34. Tapered end 34 provides ease ofentry and centering in a storage compartment (not shown). Cover flange36 partially closes end 34 and has locking shoulder 38 for sealingengagement with base 28 via resilient washer 40. Cover portion 42adjacent open end 32 is tapered at the inner surface to a reducedthickness.

Base 28 is a single flange spool including cylindrical hub or coreportion 44 with spool flange 46 fixed to the hub at one end. End 48 ofhub 44 opposed to flange 46 is hollow for receiving sleeve 10 havingresilient locking fingers 52. The hub is designed to carry a flexiblewound web 54, shown in phantom, for example, in the fonn of magnetictape, on the hub surface bounded by spool flange 46 and resilientfingers 52. The face of spool flange 46 opposed to hub 44 includes aclutch surface in the form of serrations 56 circumferentially spacedaround magnetically permeable disk 22. Deformable skirt 58 extends at anangle from the periphery of spool flange 46 away from hub 44.

When cover 26 and base 28 are brought together, hub 44 and web 54 extendinto and are surrounded by the open tubular portion of cover 26. Asclosure is continued, cam surfaces 62 of resilient fingers 52 come intocontact with annular cover flange 36. This action flexes fingers 52inwardly to pass into and through the central opening in cover flange 36past washer 40 to locking shoulder 38. When closure is completed, camportion 62 of each resilient finger 52 extends past annular flange 36,so that the lateral inward constraint of annular flange 36 is no longerapplied to resilient fingers 52. In this unconstrained condition,resilient fingers 52 straighten; and locking teeth 64 bear axiallyagainst locking shoulder 38, see FIG. 4. With locking shoulder 38 andresilient locking fingers 52 locked together, base 28 is secured withintubular cover 26. With closure of the cartridge completed, resilientwasher 40 contacts an adjacent edge of wound web 54 to retard the webfrom unwinding inside cartridge 16.

Referring again to FIG. 4, a segment of the cartridge with cover 26 andspool 28 locked together is diagrammatically shown in simplifiedcross-section. For simplicity, in FIGS. 4 and 6, sleeve 10 is shown asan integral part of hollow spool core 44, it being understood thearrangement of FIGS. 1 and 2 is used in apparatus shown in thesefigures.

Fingers 52 remain in locking contact with shoulder 38 until urgedradially inwardly. The resiliency and dimensions of the fingers is suchthat an axial force exerted between the cover and base member will notnormally release the fingers 52 from locking shoulder 38. Similarly, thenumber, array, resiliency, and dimensions of the fingers also normallyprevent manual release of the fingers from the shoulder. Fingers 56 arearrayed in such a manner and are of such stiffness that in the absenceof tool 74 (FIG. 6) they cannot normally all be depressed simultaneouslymanually without great difficulty. As long as one finger remains inlocking contact with shoulder 38, separation of the base and covermembers is not possible. Cover 26 completely encloses base 28 such thatno portion of the base can be readily grasped to remove the cover.

When base 28 and cover 26 are in closed relationship, tapered end wallcover portion 42 frictionally engages deformable skirt 58 of spoolflange 46. In a preferred embodiment, the angle of skirt 58 and theangle of tapered wall portion 42 are such that contact between the twoelements is made quickly during closure; and the seal is tight andsubstantially dust proof.

FIG. 4 also shows an annular groove 66 on the inner surface of fingers52. This radially inwardly opening groove provides for releasablelatching for engagement with detent 12 for retaining the cartridgeduring storage or conveyance. The right side of FIG. shows, in phantom,the details of one form of detent 12. A number of resilient detentfingers 68 each have a beaded tip 72 for camming engagement anddisengagement with groove 66 in resilient fingers 52, as shown. Relativeaxial movement between cartridge 16 and detent 12 cams detent fingers 68inwardly until the beaded tips 72 on fingers 68 seat in groove 66 tosecure the cartridge. Cartridge 16 is disengaged from detent 12 bypulling them apart with a force exceeding the resiliency of detentfingers 68.

To remove cover 26 from base 28, as shown in FIG. 6, tool 74 has annularcam follower 76 to mate annularly disposed cam surfaces 62 on fingers 52simultaneously upon movement of tool 74 towards the cartridge. Each camsurface 62 rides on the surface of cam follower 76 to inwardly urgefingers past shoulder 38 for releasing cover 26. As shown in FIG. 6,fingers 52 are in an unlocking relation to shoulder 38, and separationof the base and cover members is being initiated by the continuing axialmovement of the tool to push spool 44 from cover 26.

In inserting and removing tubular cover 26 from the tape spool, thesliding engagement of the cams on the cam surfaces of the tubular cover,such as washer 40 of FIG. 4, may cause wear on the cammed surfaces. Suchwear may generate particulate matter, which can contaminate recordingmedia on the spool. That is, such minute debris on a recording media cancause signal dropout and, hence, recording errors. Therefore, it isextremely important that wear be reduced on camming surface 62 forreducing such debris. This is accomplished by adjusting the radius ofcurvature of camming surface 62 to that radius of the maximum radialinward deflection of locking fingers 52 rather than establishing aradius of curvature for surface 62 that is equal to the radial outwardradius of sleeve 10. In FIG. 7, two fingers 52 are shown in the radialoutward position with the solid lines 79 representing the radius ofcurvature of sleeve from its central axis 80. This is the maximum radiusof curvature. The radius of curvature of the inner annular cammingsurface on tubular cover 26 corresponds to the maximum inward deflectionof fingers 52 as from axis 81, which is substantially less than themaximum radius of curvature. This arcuate cam surface, represented bydotted line 82 engages surface 62 only at the circumferentialextremities 83 and 84 of all fingers 52. The circumferential centralportion 85 of fingers 52 initially is not engaged with the inner annularcamming surface of tubular cover 26. As a result, maximum forces areexerted at 83 and 84, resulting in increased wear. Such increased wearon camming surface 62 is alleviated by adjusting the radius of curvatureof camming surface 62 to that of dotted line 82 such that the annularinner facing camming surface of tubular cover 26 engages substantiallyall, if not all, the camming surface 62 of all fingers 52. Thissubstantial contiguous engagement across the circumferential extent ofall surfaces 62 continues throughout the radial movements of axiallyouter end portions 152 thereby minimizing wear by reducing forces to aminimum across the camming surfaces. In FIG. 7, the radial inwardposition of the two fingers 52 is indicated by dotted lines 86.. Itshould be noted that dotted lines 82 and 86 have arcuate portions whichare concentric about axes 81 and 80, respectively.

Choice of materials for the base, cover, and locking mechanism of thecartridge and detent may be such as to avoid wear and generation ofdebris within the cartridge and the storage apparatus. The various partsare constructed either of wear resistant resilient metals or plasticswhich do not deteriorate or generate particles upon contact and whichprovide sufficient stiffness to avoid manual unlocking of the cartridge.More importantly, it tends to minimize degradation (creep and fatique)with time. The choice of such materials is within the skill of the art.It is preferred that sleeve 10 be molded from an acetal resin(polyacetal), such as DELRIN or CELCON materials, no limitation theretointended.

It must also be understood that the preferred embodiments set forthhereinabove may be easily modified while leaving the resulting mechanismwithin the scope of the subject invention. For example, reversal of theparts in the locking mechanism from the cover member to the base membermay be readily achieved. Short locking fingers with longer second typefingers may also be employed. In another variation, detents 19 may be onlocking fingers 52, the radial movements of such fingers being such thata detent l9 always remains latched as shown in FIG. 1. One lockingfinger 52 per one detenting finger 17 may also be employed. From theabove discussion, is is apparent that a myriad of slot-finger selectionsare usable to practice the present invention, no limitation to theillustrated or described configurations intended.

A secondary embodiment allows tha slots to be axially aligned. While thepreferred illustrated embodiment has better force transfercharacteristics, slot and finger axial alignment permits more facilevariable stress finger loading. For example, ramp or cam 13 can beaxially slotted for receiving some of the fingers 14 in slots totransfer less force to fingers 52 (now aligned with some of the fingers14) with other fingers 14 providing stronger holding forces on fingers17. Even with offset slotting, cam 13 may have an undulating surface forvariable loading fingers 52 and 17.

While the invention has been particularly shown and described withreference to a preferred embodiment thereof, it will be understood bythose skilled in the art that the foregoing and other changes in formand detail may be made therein without departing from the spirit andscope of the invention.

What is claimed is: 1. A sleeve for insertion into a hollow core memberhaving a plurality of circumferentially displaced, radially inwardlyopening latch receptacles adjacent one end, a radially inwardlyextending annular shoulder disposed axially inward of said receptaclesfrom said one end and inside the core, and an annular camming surfacedisposed axially inward of said annular shoulder from said one end;

the improved sleeve comprising: a unitary tubular body having first andsecond axial end portions and consisting of resilient material;

an annular rib separating said first and second axial end portions andextending radially inwardly from both said axial end portions;

each axial end portion having a plurality of slots axially extendingproximately from said rib to the respective ends such that each saidaxial end portions consists of a plurality of axially extendingresilient fingers;

said slots in said first axial end portion being circumferentiallydisplaced from slots in said second axial end portion; and

said fingers being of greater circumferential extent than said slots,and the sleeve having an outside diameter greater than an insidediameter of the annular camming surface.

2. The sleeve set forth in claim 1 further including in combination:

said first axial end portion having first and second types of fingers;

said first type of fingers being locking fingers and extendingproximately from said rib to an end of said first axial end portion andincluding radially extending shoulder means adjacent said first axialend;

said second type of finger being interspersed between said first type offingers and extending axially only partially toward said first axial endand including a radially extending detent; and

said second type of finger being symmetrically disposedcircumferentially about said sleeve.

3. The sleeve set forth in claim 2 wherein each said finger of the firsttype having an outward end portion including said radially extendingshoulder of circumferentially equal dimensions and disposed about saidsleeve such that said first type fingers immediately adjacent saidsecond type fingers having a smaller circumferential extent from saiddetent on said first type finger to proximately along said rib andincluding a greater circumferential extent axially outward of saiddetent means on said second type finger.

4. The sleeve set forth in claim 3 wherein said resilient fingers insaid second axial end portion being disposed alternately with saidfingers of the first type and including a finger having acircumferential extent greater than said fingers of the second typewhereby slots in the first axial end portion adjacent said finger of thesecond type being opposite a same finger, respectively, in the secondaxial end portion extending between the immediately abutting first typefingers.

5. The sleeve set forth in claim 3 wherein said second axial end portionincludes slots extending to proximately said rib immediate said firsttype fingers and including shorter axially extending slotscircumferentially aligned with said second type fingers and beingfurther from said rib than said first type finger circumferentiallyaligned slots.

6. The sleeve set forth in claim 1 wherein all of said slots extend intosaid rib and effectively terminate substantially on the samecircumference of said sleeve whereby a bending moment action between thefirst and second axial end portions is established via said rib.

7. The sleeve set forth in claim 6 wherein said rib includes a radiallyinwardly extending continuous circur'nferentially enlarged portion.

8. The sleeve set forth in claim 6 wherein said second axial end portionis shorter than said first axial end portion;

said first axial end portion having first and second type fingers, saidfirst type of fingers extending axially to the entire length of saidfirst axial end portion and said second type of fingers extending onlypartially the length of said first axial end portion;

said second type fingers being symmetrically disposed circumferentiallyabout said sleeve and including radially extending detents at the outerend portions;

said first type fingers having radially outwardly extending shoulders attheir outer end portions, each circumferential extent of said first typefingers at the outer end portion being identical such that said firsttype fingers adjacent said second type fingers including a portionextending axially outward of said detent means; and

said first type fingers further including a camming surface extendingfrom said radial shoulder outward end to the radial inward side of saidfirst type fingers for forming a camming surface for enabling urgingsaid first type fingers radially inward for closing the slots adjacentsaid outward end portions of said first type fingers.

9. The sleeve set forth in claim 8 wherein there are twice as many firsttype fingers as second type fingers, and said second axial end portionslots being circumferentially aligned between slots on adjacent sides ofeach of said first type fingers with no slots being circumferentiallyaligned with said second type fingers such that fingers in said secondportion being of different circumferential extent with the ones adjacentsaid second type fingers being of greater circumferential extent thanothers of said fingers in said second axial end portion.

10. The sleeve set forth in claim 9 wherein said second type fingers ofsaid first axial end portion having radially outwardly extending detentsat the respective outermost axial end portion thereof; and

said outer end portions of said first type fingers having a radius onsaid camming surfaces circumferentially of said sleeve less than theradius of said sleeve when in its radially expanded position.

11. The sleeve set forth in claim 1 wherein said slots from both of saidaxial end portions extend into said rib to terminate on differentcircumferences of said sleeve whereby the bending moment between thefirst and second axial end portions is decreased as measured whenterminating said slots on the same circumferential or common line.

12. The sleeve set forth in claim 11 wherein said rib includes acontinuous circumferentially extending enlarged portion which extendsradially inwardly.

13. The sleeve set forth in claim 1 wherein slots in said second endportions terminate short of but in juxtaposition to said rib, while theslots in said first end portion terminate axially inside said rib, andsaid first axial end portion having a greater axial extent than saidsecond axial end portion, and said fingers in said first end portioneach including a radially extending portion for locking engagement withanother member; and

a first group of said first portion fingers having said radiallyextending shoulders at the axial outer end of said first portion, whileothers of said fingers have said radially extending shouldersintermediate said first radially extending shoulders and said rib.

14. The sleeve set forth in claim 1 further including a radiallyoutwardly extending detent means and radially outwardly extendinglatching means on said fingers in one of said axial end portions.

15. A sleeve for insertion into a hollow core member and having aplurality of circumferentially displaced, radially inwardly openinglatch receptacles adjacent one end, a radially inwardly extendingannular shoulder axially inward of said receptacles with respect to saidone end and inside the core, and an annular camming surface axiallyinwardly of said annular shoulder,

the improved sleeve comprising:

a unitary cylindrical body having first and second axial end portionsand consisting of resilient molded plastic type material;

an axially central annular portion separating said first and secondaxial end portions;

each axial end portion having a plurality of slots axially extendingfrom said annular portion to the respective ends such that each saidaxial end portion consists of a plurality of axially extending resilientfingers;

said first axial end portion having a greater axial extent than saidsecond axial end portion;

said axially extending fingers in said first axial end portion being offirst and second types, a plurality of fingers of each said type, saidsecond type fingers having a radially outward extending locking portionat the axial outward extremity of said first axial end portion, saidsecond type finger having a radially outwardly extending detent portionaxially intermediate said annular portion and said locking portions; and

at least one first type finger being circumferentially interposedbetween any two of said second type fingers.

16. A sleeve for insertion into a hollow core member and having aplurality of circumferentially displaced, radially inwardly openinglatch receptacles adjacent one end, a radially inwardly extendingannular shoulder axially inward of said receptacles with respect to saidone end and inside the core, and an annular camming surface axiallyinwardly of said annular shoulder,

the improved sleeve comprising:

a unitary cylindrical body having first and second axial end portionsand consisting of resilient material;

each axial end portion having a plurality of slots axially extendingfrom the respective ends substantially to a common circumferential lineabout said sleeve such that each said axial end portion consists of aplurality of extending resilient fingers axially extending from saidcommon circumferential lines;

said slots in said first axial end portion being circum' ferentiallydisplaced from slots in said second axial end portion; and

said first axial end portion having some fingers longer than others witheach said other fingers being circumferentially interposed between twoof said some fingers, each said fingers having radially extending detentportions at their respective axial outer end portions.

17. A releasable latching assembly for selective releasable engagementwith an annular latch,

the improvement including in combination:

a body member to be latched having an axis of latching and a concentriccylindrical cavity;

a first portion of said cavity having a first inside diameter andincluding latch receptacles symmetrically disposed about the cavity;

an axially outwardly facing shoulder at the inner end of saidcylindrical cavity and a frustro-conical surface extending axiallyinward concentric with said axis from said outwardly axially facingshoulder;

a resilient tubular sleeve disposed in said cavity and having first andsecond axial end portions;

an axially central annular portion separating said first and secondaxial end portions and disposed in said cylindrical cavity intermediatesaid axially facing shoulder and said locking means;

said sleeve having an outside diameter less than the inside diameter ofsaid cylindrical portion, but an outside diameter greater than theinside diameters of said frustro-conical section;

each axial end portion of said sleeve having a plurality of slotsaxially extending from said central annular portion to the respectiveends of said sleeve, such that each said axial end portion consists of aplurality of axially extending resilient fingers;

said slots in said first axial end portion being circumferentiallydisplaced from said slots in said second axial end portion;

said first axial end portion having a greater axial extent than saidsecond axial end portion;

said frustro-conical surface radially inwardly urging fingers in saidsecond axial end portion whereby fingers in said first axial end portionare radially outwardly urged with the central portion of said sleevebeing free to move within said first cylindrical cavity;

said axially extending fingers in said first axial end portion being offirst and second types, a plurality of such fingers of each said type,said second type fingers having a radially outwardly extending lockingportion extending respectively into said receptacles in said surface ofsaid cylindrical cavity and being symmetrically disposedcircumferentially of said sleeve, each said first type of fingersextending outwardly of said cylindrical cavity and including a radialoutwardly extending locking shoulder substantially parallel to a surfaceof said member to be latched immediately adjacent and circumferentiallydisposed with respect to said cylindrical cavity;

the arrangement being such that the radial inward urging on said fingersin said second axial fingers urges the fingers in said first axial endportion radially outwardly in a symmetrical uniform manner.

18. The assembly set forth in claim 17 wherein said central annularportion includes a continuously circumferentially extending radiallyinwardly extending enlarged portion.

19. A releasable latching assembly for selective releasable engagementwith an annular latch,

the improvement including in combination:

a body member to be latched having an axis of latching and a concentriccylindrical cavity;

a first portion of said cavity having a first inside diameter andincluding latch receptacle means symmetrically disposed about saidcavity;

an axially outwardly facing shoulder at the inner end of saidcylindrical cavity and a frustro-conical surface extending axiallyinward from said outwardly axially facing shoulder and concentric withsaid axis;

a resilient tubular sleeve disposed in said cavity and having first andsecond axial end portions;

an axially central annular portion separating said first and secondaxial end portions and disposed in said cylindrical cavity intermediatesaid axially facing shoulder and said locking means;

said sleeve having an outside diameter less than the inside diameter ofsaid cylindrical portion, but an outside diameter greater than theinside diameters of said frustro-conical section;

each axial end portion of said sleeve having a plurality of slotsaxially extending from said central annular portion to the respectiveends of said sleeve, such that each said axial end portion consists of aplurality of axially extending resilient fingers;

said frustro-conical surface radially inwardly urging fingers in saidsecond axial end portion whereby fingers in said first axial end portionare radially outwardly urged with the central portion of said sleevebeing free to move within said first cylindrical cavity;

the arrangement being such that the radial inward urging on said fingersin said second axial fingers urges the fingers in said first axial endportion radially outwardly in a symmetrical uniform manner.

1. A sleeve for insertion into a hollow core member having a pluralityof circumferentially displaced, radially inwardly opening latchreceptacles adjacent one end, a radially inwardly extending annularshoulder disposed axially inward of said receptacles from said one endand inside the core, and an annular camming surface disposed axiallyinward of said annular shoulder from said one end; the improved sleevecomprising: a unitary tubular body having first and second axial endportions and consisting of resilient material; an annular rib separatingsaid first and second axial end portions and extending radially inwardlyfrom both said axial end portions; each axial end portion having aplurality of slots axially extending proximately from said rib to therespective ends such that each said axial end portions consists of aplurality of axially extending resilient fingers; said slots in saidfirst axial end portion being circumferentially displaced from slots insaid second axial end portion; and said fingers being of greatercircumferential extent than said slots, and the sleeve having an outsidediameter greater than an inside diameter of the annular camming surface.2. The sleeve set forth in claim 1 further including in combination:said first axial end portion having first and second types of fingers;said first type of fingers being locking fingers and extendingproximately from said rib to an end of said first axial end portion andincluding radially extending shoulder means adjacent said first axialend; said second type of finger being interspersed between said firsttype of fingers and extending axially only partially toward said firstaxial end and including a radially extending detent; and said secondtype of finger being symmetrically disposed circumferentially about saidsleeve.
 3. The sleeve set forth in claim 2 wherein each said finger ofthe first type having an outward end portion including said radiallyextending shoulder of circumferentially equal dimensions and dIsposedabout said sleeve such that said first type fingers immediately adjacentsaid second type fingers having a smaller circumferential extent fromsaid detent on said first type finger to proximately along said rib andincluding a greater circumferential extent axially outward of saiddetent means on said second type finger.
 4. The sleeve set forth inclaim 3 wherein said resilient fingers in said second axial end portionbeing disposed alternately with said fingers of the first type andincluding a finger having a circumferential extent greater than saidfingers of the second type whereby slots in the first axial end portionadjacent said finger of the second type being opposite a same finger,respectively, in the second axial end portion extending between theimmediately abutting first type fingers.
 5. The sleeve set forth inclaim 3 wherein said second axial end portion includes slots extendingto proximately said rib immediate said first type fingers and includingshorter axially extending slots circumferentially aligned with saidsecond type fingers and being further from said rib than said first typefinger circumferentially aligned slots.
 6. The sleeve set forth in claim1 wherein all of said slots extend into said rib and effectivelyterminate substantially on the same circumference of said sleeve wherebya bending moment action between the first and second axial end portionsis established via said rib.
 7. The sleeve set forth in claim 6 whereinsaid rib includes a radially inwardly extending continuouscircumferentially enlarged portion.
 8. The sleeve set forth in claim 6wherein said second axial end portion is shorter than said first axialend portion; said first axial end portion having first and second typefingers, said first type of fingers extending axially to the entirelength of said first axial end portion and said second type of fingersextending only partially the length of said first axial end portion;said second type fingers being symmetrically disposed circumferentiallyabout said sleeve and including radially extending detents at the outerend portions; said first type fingers having radially outwardlyextending shoulders at their outer end portions, each circumferentialextent of said first type fingers at the outer end portion beingidentical such that said first type fingers adjacent said second typefingers including a portion extending axially outward of said detentmeans; and said first type fingers further including a camming surfaceextending from said radial shoulder outward end to the radial inwardside of said first type fingers for forming a camming surface forenabling urging said first type fingers radially inward for closing theslots adjacent said outward end portions of said first type fingers. 9.The sleeve set forth in claim 8 wherein there are twice as many firsttype fingers as second type fingers, and said second axial end portionslots being circumferentially aligned between slots on adjacent sides ofeach of said first type fingers with no slots being circumferentiallyaligned with said second type fingers such that fingers in said secondportion being of different circumferential extent with the ones adjacentsaid second type fingers being of greater circumferential extent thanothers of said fingers in said second axial end portion.
 10. The sleeveset forth in claim 9 wherein said second type fingers of said firstaxial end portion having radially outwardly extending detents at therespective outermost axial end portion thereof; and said outer endportions of said first type fingers having a radius on said cammingsurfaces circumferentially of said sleeve less than the radius of saidsleeve when in its radially expanded position.
 11. The sleeve set forthin claim 1 wherein said slots from both of said axial end portionsextend into said rib to terminate on different circumferences of saidsleeve whereby the bending moment between the first and second axial endportions iS decreased as measured when terminating said slots on thesame circumferential or common line.
 12. The sleeve set forth in claim11 wherein said rib includes a continuous circumferentially extendingenlarged portion which extends radially inwardly.
 13. The sleeve setforth in claim 1 wherein slots in said second end portions terminateshort of but in juxtaposition to said rib, while the slots in said firstend portion terminate axially inside said rib, and said first axial endportion having a greater axial extent than said second axial endportion, and said fingers in said first end portion each including aradially extending portion for locking engagement with another member;and a first group of said first portion fingers having said radiallyextending shoulders at the axial outer end of said first portion, whileothers of said fingers have said radially extending shouldersintermediate said first radially extending shoulders and said rib. 14.The sleeve set forth in claim 1 further including a radially outwardlyextending detent means and radially outwardly extending latching meanson said fingers in one of said axial end portions.
 15. A sleeve forinsertion into a hollow core member and having a plurality ofcircumferentially displaced, radially inwardly opening latch receptaclesadjacent one end, a radially inwardly extending annular shoulder axiallyinward of said receptacles with respect to said one end and inside thecore, and an annular camming surface axially inwardly of said annularshoulder, the improved sleeve comprising: a unitary cylindrical bodyhaving first and second axial end portions and consisting of resilientmolded plastic type material; an axially central annular portionseparating said first and second axial end portions; each axial endportion having a plurality of slots axially extending from said annularportion to the respective ends such that each said axial end portionconsists of a plurality of axially extending resilient fingers; saidfirst axial end portion having a greater axial extent than said secondaxial end portion; said axially extending fingers in said first axialend portion being of first and second types, a plurality of fingers ofeach said type, said second type fingers having a radially outwardextending locking portion at the axial outward extremity of said firstaxial end portion, said second type finger having a radially outwardlyextending detent portion axially intermediate said annular portion andsaid locking portions; and at least one first type finger beingcircumferentially interposed between any two of said second typefingers.
 16. A sleeve for insertion into a hollow core member and havinga plurality of circumferentially displaced, radially inwardly openinglatch receptacles adjacent one end, a radially inwardly extendingannular shoulder axially inward of said receptacles with respect to saidone end and inside the core, and an annular camming surface axiallyinwardly of said annular shoulder, the improved sleeve comprising: aunitary cylindrical body having first and second axial end portions andconsisting of resilient material; each axial end portion having aplurality of slots axially extending from the respective endssubstantially to a common circumferential line about said sleeve suchthat each said axial end portion consists of a plurality of extendingresilient fingers axially extending from said common circumferentiallines; said slots in said first axial end portion beingcircumferentially displaced from slots in said second axial end portion;and said first axial end portion having some fingers longer than otherswith each said other fingers being circumferentially interposed betweentwo of said some fingers, each said fingers having radially extendingdetent portions at their respective axial outer end portions.
 17. Areleasable latching assembly for selective releasable engagement with anannular latch, the improvement including in combination: a body memberto be latched having an axis of latching and a concentric cylindricalcavity; a first portion of said cavity having a first inside diameterand including latch receptacles symmetrically disposed about the cavity;an axially outwardly facing shoulder at the inner end of saidcylindrical cavity and a frustro-conical surface extending axiallyinward concentric with said axis from said outwardly axially facingshoulder; a resilient tubular sleeve disposed in said cavity and havingfirst and second axial end portions; an axially central annular portionseparating said first and second axial end portions and disposed in saidcylindrical cavity intermediate said axially facing shoulder and saidlocking means; said sleeve having an outside diameter less than theinside diameter of said cylindrical portion, but an outside diametergreater than the inside diameters of said frustro-conical section; eachaxial end portion of said sleeve having a plurality of slots axiallyextending from said central annular portion to the respective ends ofsaid sleeve, such that each said axial end portion consists of aplurality of axially extending resilient fingers; said slots in saidfirst axial end portion being circumferentially displaced from saidslots in said second axial end portion; said first axial end portionhaving a greater axial extent than said second axial end portion; saidfrustro-conical surface radially inwardly urging fingers in said secondaxial end portion whereby fingers in said first axial end portion areradially outwardly urged with the central portion of said sleeve beingfree to move within said first cylindrical cavity; said axiallyextending fingers in said first axial end portion being of first andsecond types, a plurality of such fingers of each said type, said secondtype fingers having a radially outwardly extending locking portionextending respectively into said receptacles in said surface of saidcylindrical cavity and being symmetrically disposed circumferentially ofsaid sleeve, each said first type of fingers extending outwardly of saidcylindrical cavity and including a radial outwardly extending lockingshoulder substantially parallel to a surface of said member to belatched immediately adjacent and circumferentially disposed with respectto said cylindrical cavity; the arrangement being such that the radialinward urging on said fingers in said second axial fingers urges thefingers in said first axial end portion radially outwardly in asymmetrical uniform manner.
 18. The assembly set forth in claim 17wherein said central annular portion includes a continuouslycircumferentially extending radially inwardly extending enlargedportion.
 19. A releasable latching assembly for selective releasableengagement with an annular latch, the improvement including incombination: a body member to be latched having an axis of latching anda concentric cylindrical cavity; a first portion of said cavity having afirst inside diameter and including latch receptacle means symmetricallydisposed about said cavity; an axially outwardly facing shoulder at theinner end of said cylindrical cavity and a frustro-conical surfaceextending axially inward from said outwardly axially facing shoulder andconcentric with said axis; a resilient tubular sleeve disposed in saidcavity and having first and second axial end portions; an axiallycentral annular portion separating said first and second axial endportions and disposed in said cylindrical cavity intermediate saidaxially facing shoulder and said locking means; said sleeve having anoutside diameter less than the inside diameter of said cylindricalportion, but an outside diameter greater than the inside diameters ofsaid frustro-conical section; each axial end portion of said sleevehaving a plurality of slots axially extending from said central annularportion To the respective ends of said sleeve, such that each said axialend portion consists of a plurality of axially extending resilientfingers; said frustro-conical surface radially inwardly urging fingersin said second axial end portion whereby fingers in said first axial endportion are radially outwardly urged with the central portion of saidsleeve being free to move within said first cylindrical cavity; thearrangement being such that the radial inward urging on said fingers insaid second axial fingers urges the fingers in said first axial endportion radially outwardly in a symmetrical uniform manner.